The four zones in Colorado — all in the San Luis Valley — cover 16,309 acres. Parcels in Saguache and Conejos counties were put up for bid.

The tepid response probably was the result of market uncertainties, said Ken Borngrebe, environmental-permitting manager for Tempe, Ariz.-based solar developer First Solar.

Borngrebe attended the auction as an observer.

The question for any developer looking at a site hinges on access to transmission, the cost of land and the market price for the solar power, Borngrebe said.

The San Luis Valley sites have access to transmission, and the minimum bid prices for the parcels ranged from about $3,350 to $4,280 — which, Borngrebe said, are low prices.

“It may come down to the lack of confidence in the market for solar today,” Borngrebe said.

Another factor may be regulatory uncertainty, said Ken Johnson, a spokesman for the Solar Energy Industries Association, a trade group.

“Financing large solar projects continues to be a challenge for the industry,” Johnson said in an e-mail.

“In this particular case, there’s an added issue which may have prompted developers to take a pass on the Colorado lease sale,” Johnson said. “The ground rules are still very much in question. To date, BLM has yet to finalize any regional mitigation plans. Frankly, it’s not smart business to commit to something until you’ve read the fine print.”

Since 2009, the bureau has approved 47 renewable-energy projects on public land, including more than 8,000 megawatts from 25 solar projects, 4,700 megawatts from 10 wind projects, and about 600 megawatts from 12 geothermal projects.

“We are disappointed not to see any bidders,” said Alex Daue, renewable-energy coordinator for the Wilderness Society, a national environmental group. “This is still the right way to plan and guide development so we meet our clean-energy goals.”

The lack of bids doesn’t mean that the parcels will not be available for solar-plant development, said Vanessa Lacayo, a BLM spokeswoman.

While state education officials are sharing their proposals aimed at ending the teacher shortage in Colorado, the state’s largest teacher association says the overall plan lacks specifics and shortchanges traditional preparation programs.